1. Field of the Invention
The present invention generally relates to semiconductor substrate processing systems and, more particularly, to matching circuits for matching the impedance of a plurality of RF sources coupled to a single electrode to the impedance of a plasma.
2. Description of the Related Art
Plasma enhanced semiconductor processing chambers are widely used in the manufacture of integrated devices. In most plasma enhanced semiconductor chambers, multiple radio frequency (RF) generators are utilized to form and control the plasma. Some plasma enhanced processing chambers feed RF power from multiple sources to a single electrode that couples the power to the plasma. However, in those embodiments, each RF source generally requires separate feed structures (e.g., separate RF generator, match output, coaxial cables to the electrode, and the like).
Therefore, there is a need for an improved apparatus for semiconductor substrate processing that utilizes a single feed structure to couple RF power from multiple RF sources to an electrode.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.